


Upon The Ancient, Savage Tide

by pocketjoong



Category: ATEEZ
Genre: Alternative Universe - Modern Fantasy/Horror, Background Kim Hongjoong/Jeong Yunho, Dom/sub Undertones, Implied/Referenced Child Abuse, M/M, Optional endings! READ AUTHORS NOTES, Past Choi San/Jung Wooyoung, Ritual Sex, Shameless Smut, Tentacle Sex, Tentacles, Yep there's monsterfucking, set in the early 90s
Language: English
Status: Completed
Published: 2020-05-12
Updated: 2020-05-11
Packaged: 2021-03-02 22:40:25
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 13,199
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24124513
Author URL: https://archiveofourown.org/users/pocketjoong/pseuds/pocketjoong
Summary: San was a drifter: he let the wind take him anywhere as long as it kept him one step ahead of his past.It was a difficult life, and a lonely one - until the wind landed him in a crumbling seaside town, home to a pretty boy named Yeosang... and something far more sinister.
Relationships: Choi San/Kang Yeosang/Park Seonghwa
Comments: 21
Kudos: 140
Collections: leviathanfest





	1. Upon The Ancient, Savage Tide

**Author's Note:**

> For Leviathanfest Prompt 7: Tentacles
> 
> Did I finish this on time? Yes. Did my PC then die so I couldn't post for a week? Yes. 
> 
> CHOOSE YOUR ENDING  
> If you like your horror open-ended and grim, the story ends for you at chapter 1. 
> 
> If, like me, you're a softhearted binch and need a happy resolution, read the optional chapter 2.

When Yunho and Hongjoong had invited San to hitch a ride to their next destination, describing it as a 'beach resort', he had kind of expected more than… this place. Maybe some nice scenery and chill surfer vibes rather than the run-down amusement parks and mobs of teens smoking weed under the pier. It was the kind of 'beach resort' that had probably been very trendy and popular in the sixties and then had been left to rot, now a soulless tourist trap only populated by backpackers, students and locals who'd invested too much to leave. 

On the very first night, San had wound up in a fight with some asshole getting handsy with a frightened girl in a beach hut, ending up with a bloody nose and a police warning for his trouble. Fueled by anger, he'd ended up getting so wasted that he used a payphone to call Wooyoung's number. He'd been drunk enough that his own name was a chore to remember, but somehow that little string of digits always made its way to the front of his mind. The call went straight to voicemail, and San wondered if Mingi had finally convinced Wooyoung to unplug the phone line at night so that he could sleep. He wasn't sure whether to be hurt or relieved that Wooyoung might not be waiting for his calls; that he might not beg San to come home again next time. He woke up the next day with his eyes feeling gritty from crying, Yunho and Hongjoong crammed onto the shitty backpackers' mattress with him like the overgrown puppies they were. 

Usually, a night like that would be enough to put him on the next bus out of a place, no matter how easy it was to find cash-in-hand work in the off season, but Hongjoong managed to wheedle him into just a few nights more. San told himself that it was just because he was sick of rooming in hostels with strangers who stole his stuff and brought girls back for mediocre sex at ass o'clock in the morning. The reality was that somehow, in their time picking grapes for shockingly low pay at a vineyard, Hongjoong and Yunho had wormed their way into the tiny remaining fragment of San's heart, meaning that he was hopelessly weak to say no to them.

And well, San had always loved the sea. Even in this place, with its flickering neon and crumbling paint, the sea was beautiful. Under the overcast skies, the water had darkened to a cruel iron grey, the currents savage and bitterly cold as though to ward off any lingering desire to swim. San did it anyway, of course, revelling in the thrill of an empty beach and stinging cold up to his navel, the salt air searing his lungs and numbing his senses until he could feel his heartbeat in his ears. The sea made him feel alive in a way that few things did these days. And so, he stayed. 

San found work in the same run-down arcade as Yunho and they spent their first few shifts discussing games and anime and yelling at the kids who tried to jostle the ancient coin shelf machines for extra money. Hongjoong got called up to be a server at the tacky Hawaiian-themed bar across the road and Yunho glowered miserably as he flirted his way into tips and carefully folded local girls' numbers into his pocket with a sly little wink. San had eventually taken pity and told him that Hongjoong emptied his pockets into the kitchen bin at the end of every evening, which brightened Yunho up considerably. Now, though, the man couldn't seem to concentrate on anything for more than two seconds before looking over at the bar and it was driving San a little nuts. Sure, he'd been checking out the cutie in skinny jeans and a sweater for the last twenty minutes, but at least he could _multitask_ and refill the candy bar at the same time _._

"Just fuck already, christ," he complained as Yunho's brain shut down after seeing a flash of white blonde hair once again. "It's physically hurting me to watch this." 

Yunho flushed bright red, his attention snapping back to the incident report he was filling out for a moron who sprained his wrist trying to shoot zombies. 

"Don't just say it like that! I don't even know if he likes me back," he said petulantly. 

San rolled his eyes so hard it hurt. He broke his attention away from the cute guy at the claw machine so that he could jump up onto the counter and shoot an accusing glare at his friend. 

"Oh yeah, I'm sure he invites all his platonic friends on a bonding trip across the country and then turns down every hot catch in favour of staring longingly at his roommate and making comments about how fuckable he is," he said sarcastically, leaning back over the till to steal a lollipop from one of the plastic jars on the counter. 

"Joong did _not_ say that I was fuckable," Yunho squeaked, going impossibly redder. 

"He said that anyone would be stupid not to want you and that - I quote - he would pay good money to see what your hands could do," San reminded him, tearing open the lollipop wrapper and flicking it into the bin, "The poor man can't make it any more obvious. Unless maybe he wrote you a formal invitation to his ass, maybe. Is that what you're waiting for?" 

Yunho smacked him on the arm, hard enough that San nearly dropped his lollipop. He shoved it in his mouth instead, scowling. 

"I don't need an invitation just, I don't know. The right time?" Yunho whined. 

"There's never a right time," San told him seriously, "But there are chances, and you can miss them. Tell him how you feel before you break his heart, 'kay?"

"Okay," Yunho acquiesced miserably. 

"And then fuck him," San added, just in case Yunho got any ideas about him having emotions. A shrill beeping sound alerted him to the fact that one of the claw machines had just broken and San glanced over to confirm that yes, it was the one being used by cute guy. Excellent. 

"It's not that easy," Yunho complained, absently doodling a love heart onto the incident report.

"Sure it is," San mumbled around his candy, "Watch this." 

He loosened the collar on his ugly polo shirt and ran one hand through his blonde hair to mess it up, then hopped the counter again and mosied on over to the claw machine, lollipop hanging from his mouth. The cute guy was chewing his lip nervously as San approached, tugging the sleeves of his oversized sweater over his knuckles.

"I'm really sorry," he rambled immediately, "I swear I wasn't cheating or anything, it just started freaking out!" 

He was even cuter up close, dark eyes framed by long lashes, tiny waist accentuated with a thick leather belt. San pulled the lollipop out of his mouth and sent the other a lazy grin, shrugging his shoulders. He didn't miss the way the other guy's gaze lingered on his sugar-stained lips. Strike one. 

"Hey, don't worry about it, this old thing jams all the time," he explained, "Luckily I'm good with my hands." 

He put the lollipop back in his mouth, letting it push suggestively at the inside of his cheek as he crouched down to flip open the control panel under the claw machine's joystick. As per usual, it was just a loose connection caused by overenthusiastic use and he pulled the miniature flat head screwdriver from the back of his belt to clamp the wiring down again. Then he flipped the panel shut and stood up, pleased to see the blush that flowered over the cute guy's face when he was caught staring. San tugged the lollipop out of his mouth again, smirking. Strike two.

"All fixed up. It will have reset though, so however many turns you had left will be gone. But I can make it up to you?" he asked. 

The cute guy narrowed his eyes. 

"With more coins?" he asked, a little suspicious. 

"If you want, or you can tell me which toy you want and I'll win it for you," San offered confidently. 

The boy snorted in disbelief. 

"Come on, you know this thing is rigged," he said, hiding a giggle behind one sweater paw. San wanted to _ruin_ him. "You'll be here all night." 

"Or maybe I know something you don't," San teased. "Wanna bet on it?" 

The cute guy tilted his head, expression calculating. 

"Maybe. What are the terms?" 

"If I can win that toy with four coins, you let me buy you a drink later. If I can't, I'll give you free hot chocolate every time I'm working _and_ buy you a drink later," San proposed cheekily. 

Cute guy rolled his eyes. 

"There it is," he huffed, but he was smiling. "I _knew_ you were coming on to me." 

San raised his hands in surrender. 

"Is that a no?" he asked, casually rolling the lollipop to the other side of his mouth. 

"It's not a no," the guy said, all shy again. Strike three. "If you can win the penguin in three coins, you can have a drink _and_ a kiss, sound fair?" 

San hummed, pretending to think hard.

"It's a hard bargain, but you're worth it. Three coins it is." 

With that, he focussed his attention fully on the claw machine, moving the joystick in casual, expert motions to maneuver the game as he wanted. Three turns per coin meant that he had to get it right first time, but San was pretty sure he had this. He'd spent most of his teen years avoiding shouting and fists and shattered glass by skulking in small town arcades, which had granted him a widely useless but sometimes fun skillset. The perks of childhood trauma, he mused. 

The cute guy hovered nervously at his elbow to begin with, but he seemed to relax as San used up his first four turns without success. He had the accuracy to grab the fuzzy little penguin, but each time, the claw would jostle and the toy would fall from its too-weak grasp. On the fifth turn, San grabbed for the horrible little gremlin toy next to the penguin, lollipop wedged between his teeth as he concentrated on nudging his target a little further to the left.

"Missed!" the guy murmured gleefully from beside him, bouncing a little on the soles of his feet. Cute. San suppressed his own smile, not wanting to give the game away too soon. On the sixth turn, he really took his time aligning the claw above the penguin, then confidently hit the button that would set the game in motion. As per usual, after five weak grabs, the claw increased its pressure and got a firm hold on the little toy. It slipped a bit when the mechanism jostled it, but stayed securely in the metal grasp as it headed towards the prize slot. 

"No way!" the cute guy gasped, bouncing excitedly. San let go of the controls and pumped his fist close to his body in victory as the machine relinquished its prize and he ducked down to pick up the penguin from the slot. 

"One penguin toy, in _two_ coins," he announced smugly. The boy accepted the gift happily, running his thumbs gently over its fluffy stomach. 

"It's so cute," he muttered to himself, then turned to smile at San. "Since you got it in two coins, you can have my name, too. I'm Yeosang," he offered shyly. 

"Pretty name," San said. "I'm San, nice to meet you." 

There was an awkward pause and San huffed a laugh, rolling his lollipop between two fingers like a cigarette.

"You don't really have to kiss me if you're too shy," he allowed, "Or we can save it for after the drink if you feel like it later." 

Yeosang pouted, his dark eyes glinting with something dangerous.

"What makes you think I'm shy?" he asked. That was all the warning San got before a surprisingly strong hand grasped the front of his work uniform and tugged him forward, Yeosang leaning in to meet his lips halfway. He didn't waste any time deepening the kiss, sliding his tongue past San's lips to steal the taste of sugar from his mouth. Yeosang tasted faintly of sea salt, as though he'd been swimming, and San wondered if he wasn't the only one mad enough to brave the ocean at this time of year. He let out an involuntary little sound as Yeosang slowly pulled back, San's lower lip caught between his teeth. He let San go and then stepped back, looking flushed and pleased with himself. 

"So you'll be at the beach tonight?" he asked sweetly.

San blinked, dazed.

"The beach?" he asked stupidly.

"In the off-season, us locals get together on a Friday night and build a bonfire," Yeosang told him, still dangerously up in his space, "There's music and drinking - it's fun, just ask anyone. You can bring your friends too." 

"We'll be there," San promised, before he could even think about it. 

"I'll look for you," Yeosang said. "Don't forget my drink. I like sweet things." 

With that, he took the forgotten lollipop from San's frozen hand and put it in his own mouth, then sauntered out with his penguin clutched to his chest. As soon as the door swung shut, a low whistle came from the counter and San turned to see Yunho staring at him with an awed expression. 

"Dude, that was something else," he said as San wandered back over to the counter. "How do you do that? And can I take you up on your offer to blow me?" 

San snorted, broken out of his daze. 

"That offer was retracted as soon as I figured out there were feelings involved. Though I'm sure Hongjoong would do it if you asked him." 

That set off a new round of useless gay whining, but San was only half paying attention, too busy daydreaming about Yeosang's pretty mouth locked around that neon pink lollipop. 

  
  


The arcade closed at three in the off season and it only took a few minutes to power down and lock up, so San was out of his dusty uniform and into a liquor store by three-thirty, one pouty Yunho in tow. 

San squinted at the cash in his wallet and wrote off the caramel vodka, instead wandering over to a fridge of premixed bottles that he hadn't touched since he was seventeen. After some consideration, he picked out some brightly coloured fruit bottles that were more sugar than alcohol, then grabbed some less glucose-heavy drinks for himself. Asking a gaggle of crop-top clad girls got them a time and location for the beach gathering, along with a phone number that he pocketed without thinking. San split with Yunho to buy a bottle of the least shitty wine they could afford for Hongjoong, and then they headed back to their shared dorm. San showered and laid out his clothes on the bunk with a frown. His black jeans were getting faded and shabby and his t-shirt had a hole in the back of it, but it would hopefully go unnoticed at a dark beach gathering. Maybe he'd swap them out for something less worn out in the next town. He didn't bother much with the rest of his appearance, just adding a black choker and stealing Hongjoong's pot of glitter liner to bring out his eyes. His hair had gone all fluffy from the shower, but there wasn't much to be done about that. Satisfied, he flopped down on the bed with a battered sci-fi novel he'd pilfered from the common room bookcase and started to read. He woke up with his face in the pages some time later to the sound of Hongjoong stomping across the room in his oversized boots. 

"Good morning," the older man chirped as San slouched up into a sitting position. "Yunho tells me we're heading to a beach party to get you a man." 

San yawned, shaking his head to clear the fog.

"That's the plan," he agreed dreamily. "You should see him, Joong. He's got thighs like Wonder Woman." 

"Hmm, not my type," Hongjoong said dismissively, leaning in close to the mirror so that he could smudge grey eyeshadow into his lash line. San snickered.

"No, your type is all six feet tall, baby face, head over heels in love with you," he quipped, dodging the pair of underwear that was thrown at his head. 

"Don't be mean," Hongjoong pouted, smearing glitter onto his cheekbone. "Especially when you've made out with him and I haven't." 

San groaned. 

"Are you still caught up on that? Hongjoong, I made out with you too! I make out with everyone! If you don't make your move tonight, I swear to god I'll tell him what you told me when we were doing tequila shots at the winery," he threatened.

Hongjoong whipped around, scandalised. 

"You wouldn't." 

"I _would,_ " San insisted, placing a hand over his heart. "This has gone on too long. It'll haunt me forever if you guys don't get together before we part ways." 

Hongjoong frowned at him.

"Then maybe we shouldn't get together, to make you stay," he suggested huffily. "You can come back to the city with us and meet our baby Jongho." 

San laughed, rolling onto his front so that he could snatch his book off the floor.

"Nobody can make me stay," he declared. "I'm a wild bird, it's bad luck to keep me in your house." 

He'd meant the words as a joke, but the following silence was heavy and cold and San knew that Hongjoong was about to ask difficult questions again. 

"Sannie, I -" 

"- wallet!" Yunho yelled, kicking open the door. He stumbled in and collapsed on top of San, effectively breaking the mood and almost tearing the front cover off San's book. 

"Oi!" San yelped, squirming free to inspect the damage. Yunho didn't seem to notice, too busy puffing and waving his tatty leather wallet victoriously.

"Left it at the liquor store," he panted, "Luckily some honest lady handed it in without even taking anything."

"You don't deserve the sheer amount of luck you get," Hongjoong complained, turning back to the mirror. "What's this, the fourth time you've had your money returned after losing it?" 

"Fifth," Yunho said smugly, then seemed to catch sight of Hongjoong's tight jeans and eyeliner. "Damn, you look incredible." 

San glared and shoved him off the bed.

"Stop drooling on me, you overgrown puppy." Then he stood up and picked up his backpack, swiftly avoiding Yunho's kick at his shins. "I'm going to flirt free drinks out of that cute bartender. Come find me when you're done and we'll head to the beach." 

He paused to catch Hongjoong's eye in the mirror. 

"Tonight, or else," he threatened sweetly, then left Hongjoong to fend off Yunho's questions.

True to his word, San paid for one drink and idly flirted his way into two more before Hongjoong slid into the seat next to him with a cheesy pick up line, already giggly on wine. San patiently let him french braid his hair down one side of his head, hoping it looked more viking than schoolgirl, and donated the last of his drink to Yunho, who was pouting on the sidelines. With that, they headed down to the beach and shed their shoes, tying them by the laces to San's backpack so they wouldn't lose them overnight. It was easy to find the party, the bonfire visible from miles away and the radio blaring loudly from someone's car stereo. 

San couldn't see Yeosang amongst the people dancing or on the array of picnic rugs people were sprawled over, so he slipped into the fold with Hongjoong and Yunho, greeting the other party-goers with high fives and fist bumps. It was an easy crowd, everyone relaxed and ready to have fun, so San just wedged the bag with Yeosang's drinks into the sand and let himself get swept up in the music. Hongjoong was so effortlessly bored and cool that he had a small crowd fawning over him in a heartbeat and Yunho had had enough drinks that he'd been talked into a dance battle by a group of girls San recognised from around the hostel. One of them was the girl he'd rescued on his first night and she waved him over with a frantic kind of smile.

"Hey, you okay?" he asked. 

"Yes, thank you!" she exclaimed, "I wanted to say thanks for the assist the other night. I explained everything to the police, but you'd already disappeared," she said apologetically. 

"No harm done," San said, giving her a lazy smile. "They get that asshole?"

She scowled. 

"Nah, he's a local boy. Untouchable," she griped. "My knee in his dick should have slowed him down though." 

San snorted a laugh and she joined in, the two of them giggling like idiots until her group of friends came over and dragged her into the dance-off.

What the girls apparently hadn't realised yet was that Yunho was not only a proficient dancer, but also fuelled by enough energy to power a small town. San watched with great amusement as he expertly pulled off a girl group routine, every hair toss and hip thrust as soft and feminine as the original performers'. The gathered crowd whooped as he executed a perfect slutdrop, then whistled as he beckoned San over to be his backup dancer. The spell was broken as soon as they made eye contact during a seductive hip roll and they both dissolved into laughter, ignoring the disappointed heckling of the spectators. Then San felt the prickling sensation of someone staring at him and he knew who he would see across the bonfire before he actually looked over. 

Yeosang was stunningly beautiful in the soft light cast by the flames, his tanned skin almost golden and his eyes warmer and deeper than ever. He was dressed simply, in high-waisted ripped jeans and a white t-shirt, but the clothes accentuated his slim waist and his thighs, one of the rips in the fabric placed high enough to be dangerous. 

San clapped Yunho on the shoulder, sending the taller man staggering thanks to a combination of alcohol in his system and dry sand underfoot. Hongjoong caught him with a surprised squawk and San left them to their painful sexual tension in favour of stalking around the bonfire with his bag and throwing himself down on the sand next to Yeosang. He had his own sexual tension to chase. 

"Hey stranger," he drawled, letting his eyes be drawn to the way Yeosang's tongue chased a drop of liquid down the neck of the now-empty bottle in his hand.

"Hey," Yeosang greeted, eyes lingering on San's choker. "I thought you looked good in that arcade uniform, but it really wasn't doing you justice." 

San flushed at the unexpected come-on, busying himself with the zipper of his backpack as he replied.

"Thanks," he said, keeping his tone relaxed, "But look who's talking." 

He looked pointedly at the rips at Yeosang's thighs as he passed over a neon pink bottle, reaching out to take the empty one and stash it back in the bag. Then he got a drink out for himself and twisted the cap off, bracing for an onslaught of artificial sugar. The false strawberry taste was even worse that he'd expected, sickly and cloying despite it failing to hide the undertone of cheap vodka. He pulled a face and Yeosang giggled beside him, his drink a third gone already.

"It's so sweet," San rasped, hanging his tongue out and panting over dramatically. Yeosang smacked him on the arm, still laughing.

"I thought you'd like sweet things," he commented, "What about your lollipop?" 

San shrugged, then looked over slyly, twisting his mouth up in a way that usually had people blushing.

"That wasn't so much about the flavour. I just like having things in my mouth."

Yeosang's cheeks flooded pink and he quickly took another swig of vodka mix, trying to play it off.

"So if I'm sweet, you won't like me?" he teased, leaning in a little closer. San matched him, moving until their faces were a hand's length apart. Yeosang's eyes widened, lips falling slightly open, looking for all the world like the definition of naive innocence. 

"You look sweet," he purred, "You act sweet. But that kiss you gave me? I don't think you're sweet at all. I'd let you be mean to me." 

Yeosang's eyes flashed darker and he graced San with a brief, one-sided smile before leaning back and hiding his mouth shyly behind one hand. 

"I don't know what you're talking about," he said. "I'm just a small town boy. You're the interesting one. Tell me where you come from?" 

For an infinitely long moment, San's ears seemed to ring and Yeosang's voice went all whispery around the edges, his vision blurring like he was properly drunk. His mouth was numb, but he could feel himself talking, no doubt slurring some intoxicated nonsense that would irritate his new friend. Guilt and self-doubt rolled in and he consciously forced himself to shut up, clenching his jaw until his teeth ached. The pause stretched on infinitely, the sound of waves crashing against sand suddenly deafening, drowning out the other people on the beach. 

"San?" Yeosang asked. The world clicked back into place, vision and ears clear as they ever had been, the sea a quiet rush of noise in the background.

San looked down at the drink in his hands, suspicious, but then remembered he'd opened the bottle himself - there was no way it had been tampered with. 

"Sorry," he told Yeosang, "Just checked out for a sec. Guess I drank faster than I thought." 

Yeosang giggled again and took another gulp of pink liquid. 

"You were talking about Wooyoung?" 

"What?" San demanded, alarmed. 

"It's okay," Yeosang soothed. "I told you about my ex too, remember? It's no big deal. Might as well be fucked up about it together, right?" 

San remembered, though he was sure he hadn't a second ago. Yeosang, in love with a man who turned out to be engaged. San, in love with someone who didn't deserve to be hurt over and over every time San got scared and lashed out. 

He forced a laugh.

"Might as well," he agreed. 

"I think it's good you got out of that town," Yeosang said, staring out over the water. "Sounds like it wasn't a healthy relationship for either of you." 

"Wooyoung would never have broken it off," San found himself saying. "Not even with Mingi waiting for him. He was just too good, and me? I'm no good," he finished wryly, downing the rest of his bottle with a grimace. He pulled it away too fast, clumsy with alcohol, and pink liquid trickled down his wrist. He went to wipe it on his jeans, but there were suddenly slim, strong fingers gripping his wrist and elbow, holding him in place. Yeosang bent forward and gently kissed up the trail of sugary drink, pink tongue dipping out to chase it. San felt heat rush over him like a wave and he swore under his breath, not sure whether to be thrilled or embarrassed by Yeosang's shamelessness in a public setting. 

"I don't like good, anyway," he said, mouth lingering over the tip of San's thumb. "Wanna see somewhere cool?" His eyes glittered with excitement and San smiled.

"Sure." 

Yeosang scrambled to his feet, tugging San up with him. He made a disagreeing noise as San picked up the backpack.

"Leave that, it'll be a pain. Nobody will steal your shit, don't worry."

San shrugged and left the backpack in the sand, letting Yeosang link their fingers together with a shy smile. It felt strange, holding hands with someone. Everyone San met knew he was only theirs for a night - he always made it clear he was a traveler and wouldn't stick around. It made people care less about the little details, made them want things hot and fast and rough, which San never complained about. It made it easier not to seek out a payphone.

But this - Yeosang's warm hand capturing his own, his skin soft despite the slight grit of wet sand - this was good too. 

They walked along the sea line, close enough that the waves sometimes splashed over their bare feet, making them curse at the cold. Yeosang shrieked when San picked him up and threatened to throw him in, but he was laughing so hard that his protests were garbled and breathless. San wasn't wearing a watch, but he estimated they walked for at least fifteen minutes before Yeosang pulled him away from the sea and toward the cliffs that bordered the east side of the beach. The full moon provided enough silvery light that they could easily traverse the flat rocks at the base of the cliff wall, but San hesitated when he saw the narrow opening in the rock that they seemed to be heading for.

"Wait, we're not going in there, right?" he asked, gently pulling Yeosang to a halt. 

Yeosang turned back, eyes bright.

"Yeah!" 

"Dude, no," San said seriously, "it'll be pitch black in there." 

Yeosang laughed.

"No, it isn't. That's the cool part! Trust me," he said, the last two words sending voice whispery and resonant again. San's ears started ringing, his vision blurred and he half-felt wet sand on his feet and cold stone under his hands as the sea built up to a crescendo in his head and he couldn't _think_. 

"San?" 

San snapped back into awareness with a jolt, realizing that they were a few metres into a thin opening in the cliff, the sound of the ocean muted by jagged rock.

"Come on, slow poke, we're almost there," Yeosang trilled, laughing at his confused expression. "Don't space out on me before we have any fun." 

San followed, but he looked more closely at Yeosang's face, wondering where all this bizarre energy had come from. Sure enough, Yeosang's cheeks were flushed, sweat sticking the hair down at his temples. His eyes were different too, pupils blown wide, and San realised they were both far drunker than he'd thought. 

"Yeosang -"

"- look!" Yeosang called, pulling him out of the passage and into an open cavern. San went to speak again but stopped, mouth falling open as he caught sight of the cave. 

"Wow." 

It was essentially a closed chamber, the only visible exit being the passage they'd come from, with a crescent-shaped beach around the inside of the cavern. The sea was gently rushing back and forth against the sand, the tide coming in from some submerged opening on the cliffside wall. Parts of the cave had large stalagmites and stalactites, showing just how long this place had existed. San could see all of it because the roof of the cavern was _glowing_ , emitting a soft light that bathed the whole place in turquoise. 

"Are those glow worms?" he asked, stepping further into the cavern to get a better look. "No, bioluminescent algae," Yeosang told him, "Maybe some kind of deep sea stuff? It's pretty, right?" 

"It's beautiful," San whispered, making his way across the sand to inspect the shimmering surface of a stalagmite. Yeosang tugged on his sleeve and he turned, smiling.

"What about me?" Yeosang asked coyly, pulling San closer and guiding his hands to his waist. 

"You're very beautiful," San played along, though it was the truth. 

Yeosang surged forward to kiss him, tasting like artificial strawberry, though the hint of seawater was still there. They made out for a little while, sweet and teasing, and San couldn't help it when his jeans suddenly felt too tight, turned on despite the bizarre circumstances. Yeosang was just so _pretty_. Then he felt a tentative hand cup him through his jeans, Yeosang's fingers trembling and uncertain. He pulled back with a breathless laugh, lacing their hands together instead. 

"Don't worry about that," he murmured, "We don't need to do anything about it." 

Yeosang's cheeks darkened and he sat down on the sand, patting the ground for San to follow. San went to sit next to him, but Yeosang caught hold of his wrist and pulled, sending him overbalancing and resulting with his knees spread, straddling Yeosang's thighs. 

"Kiss me more," Yeosang demanded, eyes dark. 

San obliged, bending down to press his lips to Yeosang's jaw, careful to keep his weight balanced on his forearms in the sand. He trailed teasing, sweet kisses over Yeosang's face until the boy beneath him pouted and whined and San huffed a laugh, moving to kiss him properly. Then Yeosang's hands found his hips to pull him down, but something was wrong. His hands were shaking, hard, body tense as though anticipating a threat. San pulled back immediately, sitting back over Yeosang's shins so he didn't feel trapped or crowded.

"Hey," he soothed, "You okay? You're shaking, sweetness." 

"I'm okay," Yeosang said quickly, sitting up. His whole body was trembling, his pupils still blown wide. "I'm fine. Don't you want me?" 

San hummed and shifted so that he was sitting next to Yeosang instead of in front of him.

"Of course I want you," he said carefully, "You're gorgeous. But you're also very drunk and nervous and I think we should just chill for now."

Yeosang narrowed his eyes.

"But I'm here and you want me and there's - there's no witnesses and you're stronger than me," he said, tone confused. 

San frowned, glancing up sharply.

"What the - ? Are you saying you think I'll take advantage of you?" he asked, "Because I _won't,_ no way. Listen, why don't we just head back to the party, yeah? Get you some water?" 

He reached out to offer a hand up but Yeosang's expression twisted and he froze.

"Stop _pretending_ ," Yeosang hissed, sounding angry - wild, even. "What about that girl in the beach hut?" 

Confusion and worry sank cold in San's stomach and he let his hand fall back to his side. 

"What?"

"Didn't you force her?" Yeosang spat. "Didn't she cry?" 

San stood up and took a few steps back.

"Fuck you," he said coldly. "I don't know what sick game this is, or where you got your information from, but I'm the guy that intervened. I gave that asshole a concussion and I don't regret it. He's disgusting." 

Yeosang looked as though he'd been slapped in the face and San wondered what the hell his deal was. Some relation to the victim? Just a crazy guy out for revenge?

"You didn't… you're the one that fought him off?" he stuttered, eyes wide. 

"Well, she was doing a pretty good job of that herself, but yeah, I helped," San said. "What's it to you? What is this about?" 

Yeosang ignored him, his dark eyes flitting left and right as he dragged shaking fingers over his face. 

"Oh, oh god, I've fucked up," he muttered to himself, breathless, "I fucked up so bad." He curled up into a ball, face tucked into his knees. 

San shook his head, half tempted to just leave Yeosang here and get back to civilisation, then call the police or an ambulance or someone to come and collect the other boy. But Yeosang looked scared out of his mind and the cave was a minefield of sharp rocks and deep waters. San couldn't live with himself if he left and the poor guy freaked out and drowned. He sighed and crouched down next to Yeosang, running a soothing hand up and down his shoulder. 

"Look, I don't know what's going on, but you really don't look well," he said, voice quiet and calm. "Why don't we head back to the beach and we'll get you some water and a blanket, okay?" 

Yeosang's head snapped up at the same moment his cold fingers locked around San's wrist and his eyes seemed to flicker black at the edges, as though his pupils had swallowed up the irises and whites of his eyes. 

"You don't understand," he hissed, strangled and lisping. "He's already here." 

He rose to his feet, tugging a struggling San behind him with inhuman strength, guiding him to another large crack in the wall of the cave. 

"Please," Yeosang begged. "If you want to live, you need to hide. Don't come out until I tell you to, okay?" 

San was about throw a punch and tell him to fuck off, but then he heard it. A disturbance in the water of the cave, the sound of something landing on the pebbles on the walkway. No, not something. _Somethings._

"Yeosssssang," a voice whispered into the cave. Yeosang's eyes flickered black again and he motioned frantically at the hiding place. Numb with fear, San obeyed his instruction, the sharp rock cutting into his cheek as he scrambled into the wall. He didn't know what Yeosang was, didn't know what the hell was going on. What he did know was that he didn't want to see where that voice was coming from. That voice, harsh and melodious, like notes being drawn out from a rusted instrument, like wind flutes caught in a hailstorm. 

"Yeossssaaaangieeee," the voice called again. San watched through the tiny gap next to his eye as Yeosang stumbled clumsily over the sand and pebbles, shedding his clothes as he went. What the fuck? 

"I'm here, it's okay," he called, that odd lisp in his voice again as he squeezed past a rock, momentarily blocked from San's view.

"It's not okay," the voice cooed, full of soothing adoration, "I can feel your distress, little one. What's the matter?" 

Yeosang reappeared, feet crunching over pebbles and shells as he made his way to the water and waded in without hesitation. San had to hold in a gasp as the other boy stepped into the blue light, revealing his naked form. He was every bit as beautiful as San could have imagined, with the perfect muscle tone of a swimmer or dancer, but something was very wrong. Yeosang's eyes were large and pitch-black, shining like pools of liquid ink in his face. His nose had flattened out into a strange shape, with two slits on each side of the cartilage, and large, needle-point teeth stuck out slightly under his upper lip. His skin had taken on a mottled blue-grey colour that shimmered in the pale light and there were parallel lines carved into his throat, dark blue ridges set along each one. His sandy hair had become sleek and kelp-green, braided neatly upon his head, woven around the sharp, boney black spikes that rose up from his skull like a crown. 

"Seonghwa," he lisped, reaching out to the water as if for comfort. To San's horror, the shadows on the shore began to move, slithering over the pebbles towards Yeosang with frightening speed. He realised with a cold jolt of fear that the dark lines were not shadows at all, but tentacles. Yeosang was still facing the water, seemingly unaware of the limbs snaking their way towards him, and San stuffed his knuckles in his mouth to stop himself from crying out a warning. He needn't have worried. Yeosang startled when the first black tentacle spiralled up his leg, but then he relaxed into the hold, lovingly tilting his face up as another caressed his cheek.

"Better?" The thing asked. 

"Better," Yeosang agreed, petting the black limb that coiled around his waist. 

"Then tell me, little one. What is the matter?" 

"I messed it up," Yeosang sniffed, bringing one arm up to wipe roughly at his eyes. "I messed up the ritual again." 

The thing made a huffing, snarling noise that shook the walls of the cavern, but the tentacles did not deviate from their gentle touching. 

"Poor Yeosangie. Did you bring me another dead one? They're nice to eat, but you know I have to _kill_ them for my magic to work," the thing chastised. San's blood ran cold in his veins, his throat closing painfully around a knot of fear as he tried to breathe silently, terrified of passing out.

In the water, Yeosang sniffled. 

"No, worse. Seonghwa, please, pretty please can you be nice this time? I want him to play with," he pleaded, letting a fat, glittering tear roll down his cheek. The tentacles froze.

"Yeosang," the thing hissed, its tone cold and seething. "What have you done?" 

"I got the wrong one," Yeosang said miserably, "I brought an innocent one. He's so, so lovely Seonghwa, he's really a good -" 

"You know it doesn't work that way, little one, not with our secret." 

The tentacle around Yeosang's waist tightened, as though to keep him from running away. The others began to rise from the water, swaying in the air as though they were looking for something - looking for San. 

"He doesn't have a family!" Yeosang rushed to say, "He doesn't have a home, he's a drifter! It'll work this time, I promise." 

The tentacles relaxed a little, two more sliding up Yeosang's body to twine around his throat and arms, stroking and squeezing him like a pet. 

"Was he good to you?" the awful voice asked, almost hesitant. Yeosang shifted shyly, mumbling something San couldn't hear. The huffing, snarling sound reverberated through the cavern again and San suddenly realised that it was _laughing_. 

"Show me, then," the thing rumbled. "Show me the pretty thing and I'll decide whether we'll keep him." 

San curled further into the wall as the tentacles released Yeosang, who immediately scrambled back onto the shore as if excited. A few moments later, his alien face appeared in San's line of sight, bouncing on his heels just as he had in the arcade. Despite his transformation, he was still recognisable as the pretty boy San had won a toy for, the birthmark under his eye now visible as a mottled patch of blue on his cheek. He was monstrous, yes, but still - still a person, still a smiling face. 

"Come on, Sannie, he won't hurt you," he soothed, holding out one of his delicate hands. "I know you're scared. I can get you out alive. You just have to trust me."

San met his steady, glimmering eyes and nodded. He knew with a cold, iron certainty in his chest that he wasn't going to survive this without Yeosang's help. He reached out one trembling hand and interlaced Yeosang's icy fingers with his own, allowing the creature to help him out of the hole in the wall and guide him along the pebbled beach. San wanted to be fearless, to march down and stare the thing down like a movie character, but the truth was that the terror spiralled through him in waves, his grip on Yeosang's hand evolving into him clinging to the other man's bare arm, eyes squeezed shut against the monster. Yeosang let him hide like a child, whispering reassurances as he half-carried the human down to the water. 

"Open your eyes, come on," Yeosang hissed to him. San reluctantly followed his instruction, and froze, his brain scrambling to make sense of the information his eyes were giving him. He saw the tentacles first, of course - how could he not? They were everywhere, tangling in the shallows like eels, slithering in a mass of black matter beneath the surface. He thought for one horrible moment that they had approached the thing mid-meal, the torso of some poor soul dangling upside-down from its maw, but then he understood the _size_ of the humanoid thing he was looking at - it was almost double what a normal person should be. The being looked similar to Yeosang with his strange nose and armoured gills, but rather than Yeosang's cute, soft features, this person looked cold and regal, like some marble statue brought to life. His perfection only served to make him seem more other: his beautiful lips out of place around sharp teeth, his long lashes doing nothing to soften the bioluminescent glow of his eyes. The halo of sharp black spikes around his skull split off and out like coral, water dripping from their jagged points back into the sea below. His skin was the same blue-grey as Yeosang's but it was more pigmented where the skin was thin over bone and it gradually darkened down his chest until it was almost black around his navel and - oh. He was not being held up by the tentacles. They were _attached_ to him, like some hideous perversion of a mermaid with a mass of writhing limbs instead of a fish tail. 

As San stared in horrified, awed silence, the creature husked another snarling laugh, the motion narrowing his eyes and baring his jagged teeth. San shrank back behind Yeosang as the tentacles shifted under the water and the man's torso twisted around until he was upright, his wet green hair tangling in his spikes as he righted himself. The being was monstrous and yet somehow stunning, and San wondered if this was how astronauts felt in the face of the endless expanse of the universe - full of terror and admiration in equal measures.

"Wow," he breathed, without thinking. Yeosang turned to look at him, bringing their noses a hair away from touching. 

"Isn't he beautiful?" Yeosang asked, his breath fanning cold and wet over San's lips. San nodded, the terror fading a little further back in his mind as he came to grips with the fact that he was probably one of very few people lucky enough to see something as incredible as this. 

"Tell him your name," Yeosang encouraged. San swallowed hard, looking back at the creature hovering above the water. It was staring back with open curiosity, eyes roaming San's faded shirt and bleached hair with the same intensity with which San had inspected his inhuman form. 

"I-I'm San," he offered, voice soft and shaky. 

"I'm Seonghwa," the thing hissed, blinking slowly at him. San's curiosity overcame him and he spoke again, more clearly this time.

"What… are you exactly?" he asked. 

Seonghwa tilted his head, smiling wide. 

"I'm Seonghwa," he repeated. 

San glanced uncertainly at Yeosang, who laughed. 

"I suppose you would call me… a siren, of sorts," he explained. "As for Seonghwa… he's old and made of magic. There are many myths that seem to mention him, but they never guess his full form. A merrow, a leviathan, a rusalka, a kraken." 

"A monster," Seonghwa's voice echoed mournfully, though his eyes gave away his amusement. "And what are you?" 

San considered the question carefully, trying to come up with something that would keep the creature interested. In every fairytale, it was the quick-witted and silver-tongued that escaped with their lives. 

"A wild bird," he said eventually. "Bad luck. A dancer, a magician. Sometimes a thief." 

"Magic?" Seonghwa enquired skeptically. 

"Like this," San said, reaching into his pocket for an arcade coin. With great effort, he forced his hands to stop shaking for long enough to dance the coin over his knuckles, then he performed a simple sleight of hand to vanish it and spit it out of his mouth. 

Seonghwa made a high-pitched trilling noise, the tentacles squirming delightedly in the water. 

"I love it," he sighed discordantly. "You've taken my fancy."

"So you'll let me go?" San asked hopefully. 

Beside him, Yeosang shifted. 

"You're smart enough to know that can't happen," he said wistfully. 

San let out a trembling breath. 

"Then what?" he demanded, eyes flicking between their faces. "If you're not going to k- to kill me, then what?" 

"Then you become like us," Seonghwa purred, sliding a little closer, "You shed your mortal form and we gift you with ourselves, with magic, with the open sea." 

San closed his eyes, trying to think past the overwhelming walls of fear and disbelief that his mind was trying to construct around him. Part of him wanted to disconnect, to retreat into himself and self-sabotage as he always did, to make a run for it even though he knew he'd never get away. Maybe they'd kill him quickly and painlessly, just a short, sharp burst of teeth in his neck or stone at the back of his skull. A larger part of him wanted to live, no matter the cost or consequences. Fuelled by the rapid thrumming of his pulse, that deep-rooted human desire for survival strangled out all of his other impulses and he opened his eyes, decided. 

"What do I have to do?" 

Yeosang giggled, looping strong arms around his waist. 

"You have to give yourself to us, of course," Seonghwa rumbled, pleased. "Yeosangie will show you." 

San breathed in sharply as Yeosang's cold hand slipped under his shirt, tugging the fabric up until San complied and lifted his arms, letting him take the piece of clothing away. Then Yeosang leaned in and kissed him hard on the mouth, every bit as hot and filthy as the time in the arcade. The siren was careful to keep his sharp canines from San's lips, but San almost resented the consideration, wanting the rough, fast thrill of arousal to drown out his fear. He licked shamelessly into Yeosang's mouth, losing himself in the quiet sound torn from the other man's throat when his warm hands settled on his hips. He couldn't hold back his own startled moan when Yeosang cupped him through his jeans, confident this time, palm pressing just shy of too hard to work him up to full arousal. 

"Yeosang," he murmured against cool lips. The siren hummed, throwing his head back as San trailed hot kisses down his jaw, hesitating a little when he reached the rough skin of his throat. 

"Show me how to make you feel good," San requested, grinding forward a little desperately into Yeosang's hand. He startled as Seonghwa made a strangled noise from behind them, flushing at the fact he'd completely forgotten they had an audience. Yeosang hushed him and took San's hand in his own, guiding it between his legs. San gasped as his fingers found a long, smooth slit in the skin there, already slick with clear fluid. 

"Like this?" he checked, gently running his fingertips over the opening.

"Like tha-at," Yeosang confirmed, eyes fluttering shut as his thighs twitched. "A-ah! Just like that." 

San smirked, always smug at being able to wreck his partner, and worked his fingers a little more firmly, as though threatening to thrust in. Yeosang choked and kicked his hips forward, San flinching back in surprise as his fingertips slipped in and brushed against something twitching inside Yeosang.

"It's okay," Yeosang gasped, sagging forward to rest his head on San's shoulder. "Let me -" 

He guided San's hand again, this time encouraging him to curl his fingers into the slit, San breathing in sharply as his fingertips brushed over something firm and pulsing. He nudged the siren's hand away to explore for himself, finding a cool, ridged length that spasmed forward into his touch. Yeosang whimpered as he reached down to work San's fingers back and forth, coaxing out the wet organ until it protruded from the slit like a cock. More familiar with that particular anatomy, San moved to wrap his hand firmly around it but Yeosang curled in on himself with a harsh cry. San froze, afraid he'd hurt the siren when Yeosang looked up at him with dark, wet eyes. 

"Still sensitive," he lisped, blue tongue slipping out to wet his lips. 

"What about something softer?" San offered slyly. He freed his waist from Yeosang's weak grip and dropped to his knees, rolling his discarded shirt under his legs to protect them from the sharp shells. Yeosang let out a wounded sound, hands twitching back and forth in the air as though he didn't know what to do with them. San flinched as a few black forms slid along the pebbles beside him, winding up Yeosang's legs and wrapping his wrists tightly to keep him restrained. Yeosang went pliant under the touch, letting Seonghwa's tentacles move him as they wished. His submission was somehow reassuring and San relaxed, focussing on the task at hand. Yeosang's cock - or whatever it technically was - was nice to look at, a softer blue than the rest of him and dripping prettily with clear slick. It had a wide slit at the top and parallel pairs of soft ridges on either side, with a series of small bumps on the underside. He blew gently on the head and Yeosang squirmed, his cock twitching even at the minimal stimulation. San felt himself flush hot all over at the thought of it in his mouth and he leaned in without hesitation, grasping tightly at his own thighs as he ran his tongue softly from the base to the tip. It was cool and wet to touch, tasting of sea salt and something sweet, almost syrupy.

Yeosang went rigid and silent, holding his breath as if to hold himself back from making noise and San tutted, repeating his action with a little more pressure. Yeosang broke immediately, a sweet little cry escaping him as he threw his head back and strained against the tentacles around his wrists. 

"Isn't he pretty?" Seonghwa's snarling voice came from close behind San. San swallowed past the fear, focussed on the way Yeosang was bound beautifully above him, chest already heaving at the slightest touch.

"So pretty," he echoed, pressing the heel of his hand against his length to relieve some of the ache.

"Will you let me touch you?" Seonghwa asked. San watched as two glossy tentacles hovered at either side of his hips. 

"You won't hurt me?" he croaked, watching the way Yeosang squirmed as the appendages stroked over his inner thighs. 

"I won't hurt you," Seonghwa promised. 

San reached out hesitantly and stroked his hand over one of the tentacles, which held still for him to touch. It wasn't gelatinous or slimy, as he had feared, but instead more like feeling a muscle - almost like running his fingers over someone's tongue, but one that was smooth and cold and probably capable of crushing him. San was… more curious than any sane human probably should be. 

"You can touch," he consented, turning his attention back to Yeosang, who was starting to whine breathlessly at the neglect. He hushed the siren, concentrating on working his tongue to distract himself from the cool, smooth tentacles circling his waist and dipping beneath the waistband of his jeans. He let out a harsh breath as one hooked open the fastenings and tugged down on his belt loops, sliding the fabric down to his thighs. Yeosang whimpered above him but San couldn't quite bring himself to focus on the siren as another tentacle wrapped delicately around his cock, working up and down with a feather-light grip that did almost nothing to relieve the pressure between his legs. He made an involuntary sound, not sure whether to protest or beg, and reached down to help - to give himself something more - but two more limbs circled his wrists, pulling them firmly to rest at the small of his back. Heat washed through San's body like a tide, his mind almost immediately taking on the fuzzy, heavy high of being taken care of as his world narrowed down to the tight grip around his wrists. 

"Don't keep my pretty siren waiting," Seonghwa whispered, something pushing gently at the back of San's head to urge him forward. San obediently leant in and took the head of Yeosang's cock between his lips, careful to keep his movements light after seeing the sensitivity. Yeosang drew in a broken gasp of air, his thighs shaking as San gently bobbed down a little further, flicking his tongue over the bumps on the underside. 

"Sa- ah!" he cried, eyes glittering with overwhelmed tears once again. San took it as a good sign and pushed further forward, taking Yeosang's cock deeper and just letting the head of it sit on the back of his tongue. He pulled back and then repeated the motion, daring to add a little more pressure as Yeosang seemed to relax into the pleasure. The tentacle around his own cock tightened as if it were rewarding him, and San made a muffled sound around Yeosang, pushing him deeper into his throat. This time, when he pulled back, he dug his tongue into the slit at the head and flicked it once, jerking back in surprise as Yeosang suddenly came with a shout, body spasming as liquid spurted from the tip of his cock. San took the first of it across his lips and chin, but quickly adapted and held his tongue out to lap up and swallow the rest of Yeosang's come, which was oddly warm and sweet in his mouth. Yeosang had gone half-limp above him, fighting weakly against the tentacles holding him up, but San hardly noticed, more concerned with the way his arousal seemed to double in intensity, his skin sensitive, his muscles wound up like springs. 

"He's ready," Yeosang whined quietly, tears escaping down his cheeks. "Seonghwa he's ready, let me breed him, let me fill him up, _please,"_ he begged.

"Another time, treasure," Seonghwa crooned, "You did so well to get him ready for me. You're the loveliest creature, Sangie." 

The praise seemed to calm Yeosang down a little and Seonghwa let him sink to the floor to kneel across from San, who immediately leaned in to kiss him, soft and messy with come. 

Yeosang smiled against his lips, making use of his new freedom to cup San's face in his hands like a lover, like he was something precious and worthy. San felt the warmth of the gesture down to his toes, the chill of the night air fading away to nothingness. A drop of sweat rolled over the back of his neck and he shifted uncomfortably, his whole body suddenly feverishly hot and dry.

Seonghwa released his hold and San almost complained, but then Yeosang helped him to his feet, freeing him of the last of his clothes as he guided him to the water. A remaining fragment of his rationality told him that the water should be dangerously cold, but San's body felt like a furnace and the ocean was blissfully cool against his heated, oversensitive skin. As they waded in up to knee height, Seonghwa moved towards them with a flurry of movement under the surface and San jolted as something pushed past his calf, almost tripping him.

"Sorry, my lovely, I've got you," Seonghwa reassured. Up close, he was as beautiful as he was terrifying and San couldn't hold back a frightened sound as those needle-sharp teeth came within range of his neck. His head spun, thoughts muddled and whiplashed between evolutionary survival instincts and a consuming desire to chase the arousal building in his veins. He should scream, he thought, or struggle, or maybe bare his throat in invitation. Seonghwa seemed to sense his hesitation and he stopped moving, shifting his gaze to Yeosang.

The siren moved in close, hooking his arms around San's waist and kissing along the line of his shoulder. San could feel his arousal pressed into the small of his back and it sent a flicker of excitement up his spine, pushing the last of his fear further away. 

"It's alright," Yeosang murmured into the shell of his ear, voice low and honey-sweet once more. "We promised to make you ours, didn't we? And we'll be yours. You can trust us, San, you can let go." 

His hand curled around San's cock at the same time he grazed his teeth down the sensitive skin of his throat, and that was all it took for San to tilt forward, throwing himself cleanly over the edge.

"Please," he groaned, forcing his eyes up to meet Seonghwa's hungry gaze. "Make me yours." 

Seonghwa reached out to cup his jaw with one great hand, his palm alone spanning the whole side of San's face as he finally leaned in and kissed him. It was gentle and sweet, the creature careful not to expose his pointed teeth even as San surged forward, seeking more. Seonghwa tasted like salt air and blood; kissed like sunlight reflected on the surface of the ocean, like a riptide tugging San's heart ruthlessly beneath the water. It was intoxicating, having the attention of this infinite being, feeling the desire of the ocean itself in the pulsing, melodious sound reverberating through night air. San whimpered at the sensation of tentacles winding their way up his body, Yeosang stepping back momentarily as they settled into place. Seonghwa broke the kiss, dragging his thumb gently over San's lower lip as he eased the tentacles over him. One had bound his arms tightly behind his back, pulling until the muscles in his shoulders protested and he hissed. They accepted the limit and relaxed a little, keeping the tension on the very edge of too much. His legs were completely immobilised, feet lifted from the sand by the mass of black limbs spreading him out like an offering whilst another, thicker tentacle hooked firmly around his waist to keep him balanced. He was completely suspended, helpless to do anything but quiver as Seonghwa carried him deeper into the water, Yeosang close behind. San's breath caught at the sensation of something coiling tentatively over his throat, gentle and slow as though afraid to break him. 

Yeosang hummed from behind him, sounding amused. 

"He can take more than that, Seonghwa. You'll tell us if it's too much, won't you, lovely?" 

San agreed, lust rendering him breathless as the tentacle settled around his neck in a firm hold. Yeosang moved closer again, hands smoothing over his skin, tracing the tentacles where they were pressed against his body. He wandered lower and San keened as he trailed one finger lightly over his hole, pressing lightly. Heat flooded San's face when it gave easily, Yeosang's fingertip pressing inside him with hardly any resistance. Yeosang growled into his ear as he followed through with the motion, sliding his finger inside in one easy movement that had San choking on a gasp. 

"Expecting to get lucky?" Yeosang asked rhetorically. "Seonghwa, he's all open and slick for us." 

Seonghwa made a low noise in his chest. 

"W-wanted you to fuck me," San whined as another finger joined the first. "Ever since I saw you at the arcade." 

"That's not usually the reaction people have to me," Yeosang commented, tone curious as he worked his fingers in and out, curling them in a way that rendered San desperate in seconds. "Everyone who sees me wants to ruin _me_. They think I'm soft and pretty and easy."

"No way," San said with a breathless laugh, "I knew there was something dangerous about you. Just look at your thighs." 

Yeosang giggled, then meanly slid a third finger in, the stretch sending a small ache up San's spine. 

"F-fuck," he gasped, eyes closing involuntarily. 

"Hmmm, don't compliment him too much, he gets cocky," Seonghwa said, "And I'll have to punish him. Are you ready for me, lovely?" 

The tentacle around San's throat shifted, nudging his chin up, and he forced his eyes open, taking in Seonghwa's perfect features in the blue-green glow. 

"I'm ready for you," he breathed, awestruck. Seonghwa smiled.

"You think you are," he said, tone patronizing as he gently pushed San's hair back from his face, "Let me see." 

Behind him, Yeosang whined and his fingers flexed inside San as they were slowly drawn out. San looked back to see the reason for his complaint - a thick tentacle had curled around Yeosang's elbow, forcing him to pull away even as he pointlessly fought to keep touching San. 

"Ssssangie," Seonghwa warned, his voice steely and resonant. "I said not yet." 

Another tentacle wound up over Yeosang's cock and the siren made a wounded sound, curling in on himself in response to the overstimulation. 

"Please, I'll be good," he lisped, tongue too clumsy around sharp teeth. "Seonghwa!" 

"There's my sweet treasure," Seonghwa cooed as tears welled up in Yeosang's eyes. "San can play with you later, I promise. Now, why don't you make him feel good, hmm?" 

He released Yeosang and the siren slipped under the water, reappearing a moment later in front of San.

"Hey stranger," he whispered, eyes alight with humour despite having been scolded.

San was too far gone to react - too empty and wound up with fear.

"Kiss me," he begged, sighing in relief as Yeosang's cold lips met his own heated mouth. 

He jolted as another finger traced his rim again, then started to press inside him. 

Except, it wasn't a finger; it was slick and flexible, growing thicker with every inch that was pushed in, and San moaned around Yeosang's tongue as he realised Seonghwa was fucking him with one of his tentacles. 

The tentacle was deeper than Yeosang's fingers now, but the stretch wasn't quite as much and San pulled away from kissing for a moment to catch his breath. Seonghwa paused, perhaps to allow him to get used to the feeling of something coiling and stroking inside him. Then the tentacle flicked over his prostate and San went boneless, his forehead connecting with Yeosang's collarbone as he let out a staggered, airy whine into his cool skin. Seonghwa trilled, delighted.

"Is that good?" 

"S-seonghwa, _please_ ," San managed to groan, head spinning with arousal. He vaguely registered Yeosang sucking a bruise into his shoulder, but more of his attention was focussed on the second tentacle gently pushing in beside the first, the movement sending shocks of pleasure through his system as it forced the first tentacle more firmly against his prostate. He hissed as the stretch became more uncomfortable, the last traces of the lube he'd used to finger himself now well and truly washed away by salt water. Seonghwa made a grumbling sound deep in his chest and San looked up as he moved himself closer, pressing his torso against Yeosang's back. The siren immediately leaned back into him, nuzzling his face into Seonghwa's chest. 

"I need your help, Yeosang," Seonghwa murmured. 

"Please," Yeosang whined, breath coming high and unsteady as a slim tentacle emerged between his thighs and stroked over the slit beneath his cock. San watched, entranced, as the tentacle slid inside Yeosang's body with far less care and gentleness than Seonghwa had afforded him. The siren jolted violently and Seonghwa took his wrists in one great hand, holding them up above Yeosang's head. Two more tentacles slithered up to join the first and Yeosang writhed as they entered him, his voice ragged, ink black eyes squeezed shut. San couldn't help the twist of heat that went through him as he saw something move in Yeosang's stomach, the tentacles large and deep enough that they were visible through his skin. Seonghwa caught his eye, a wicked smile painted across his features, and San cried out as the tentacles inside him started moving again, fucking him in tandem with the three stuffed inside Yeosang. Seonghwa was merciless with the siren, one hand in a vice grip on his wrists whilst the other stroked his hair, murmuring quiet praises and assurances as Yeosang squirmed. Another tentacle slid up to caress Yeosang's cock, the tip of it working hard and fast along the ridges of it and Yeosang whined brokenly, head thrown back as he came again, clear, silvery fluid splashing over San's front as the siren choked on Seonghwa's name. 

"You're so good," Seonghwa soothed, drawing out two of the tentacles. They were coated in a slick, clear fluid and San put the pieces together as the two limbs snaked behind him. 

"Fuck," he mumbled, dizzy with the idea of Seonghwa fucking him using Yeosang's - come? Slick? " _Fuck!_ "

The second tentacle was removed and two slick, wet tips replaced it, his thighs tensing automatically at the unexpected increase in thickness. Then Yeosang's hand was on his cock, cool and wet with the same liquid and San's eyes snapped open - he hadn't even remembered closing them. Yeosang was still leaning back into Seonghwa's chest, panting quietly as a tentacle coiled slowly inside him, but both sets of eyes were focussed on San. He held his breath for a moment, then relaxed as Yeosang smiled lazily at him, sated for the moment. The tentacles slipped further inside San and for a moment he could only think about how _full_ he was, the three independent movements inside him almost overwhelming him with sensation. Seonghwa leaned down over Yeosang to kiss him again and San whined into his mouth, feeling hot and small and desperate, chasing the kiss when Seonghwa pulled back with a soft sound.

"Now you're ready for me, lovely," he said, gently wiping saliva from the corner of San's lips. "Yeosangie, are you ready for him?" 

"Mhm," Yeosang agreed. 

San let out a protest as the tentacles slowly withdrew from him and the ones restraining him relaxed slightly, bringing his feet back to the sand. His legs shook, but Yeosang quickly stepped forward to steady him, then helped him turn around so that their positions were reversed, San's back to Seonghwa whilst Yeosang faced them both. More tentacles swarmed his arms and legs again, holding him fast as Seonghwa drew in close, pressing gentle lips to his temple. Another tentacle slid up against his lower back, thicker and firmer than the others and coated in slippery fluid. 

"Just relax," Yeosang soothed, then guided San's cock into his slit just as the tentacle pushed against San's hole. 

San forced himself to breathe and made his muscles go loose, relying on Seonghwa and Yeosang to keep him upright as the tentacle slid into him, the burning only tolerable due to the slick, cool walls around his own cock. A thin tentacle pushed into Yeosang's body beside him, curling around his cock and making Yeosang snarl as he pushed back into the dual stimulation The sensation was too much and San's orgasm crashed over him like a waterfall, his mind whiting out for an impossibly long moment as pleasure shook through his body. Seonghwa continued to push and _push_ , tears collecting in San's eyelashes as the overstimulation stung and the tentacle just kept coming, longer and thicker than anything he'd ever had in his body. Yeosang had shown mercy and stopped moving, letting him recover at least a little even as Seonghwa continued to fill him up. When San finally felt a cool, moving mass of tentacles against his thighs, Seonghwa let out a high-pitched snarl, the harmonics of it echoing around the cavern. The tentacle inside San pulsed and he looked down to see that there was indeed a bulge in his stomach where it sat. His cock twitched where it was already filling again and Yeosang must have felt it, following San's eyes down to the protrusion in his middle.

"Oh, do you like that?" he asked gently, moving to stroke over the bulge with his hands. "Do you like seeing how well Seonghwa fills us up? 

Seonghwa and San groaned in unison and Yeosang pressed down harder, so that Seonghwa could feel the pressure against his tentacle. Seonghwa snarled and grasped San by the hips, hands easily spanning his waist as he pulled back and started fucking into him hard, pushing him deeper into Yeosang on every upstroke. San lost track of time and space, completely focussed on the feeling of being suspended and filled up by someone as powerful as Seonghwa. Yeosang wasn't unaffected either and another group of tentacles appeared to steady him, winding up his legs and around his waist as he started to squirm and buck forward onto San's cock. 

"So close, my sweet treasures," Seonghwa hissed, voice less human than before, "I'm going to breed both of you, make you forget everything but me. You want to be mine?" 

"Yes," San gasped against Yeosang's throat. 

"Then take it," Seonghwa snarled, and thrust deep into San one last time, coiling and throbbing as liquid gushed from the thick tentacle. Every other limb tensed and tightened, the gentle grip on San's wrists and thighs becoming bruising as the tentacle around his throat cut off his air supply entirely. Yeosang spasmed around him and the pain crashed into the pleasure, sparking the most intense, drawn out orgasm San could imagine, euphoria rolling through him in waves even as his lungs burned for air. The other tentacles loosened their grip but the one around his throat only tightened, dark spots forming in his vision as it cut off the blood flow in his carotid arteries and the panic started to set in. He tried to move his hands up to pull it off, but then Yeosang's strange, beautiful face swam into his blurry vision, holding something black and jagged in his hand. His expression was wild and hungry, his eyes narrowed, as sharp as his teeth.

"I'm sorry I lied, Sannie. It will only hurt for a moment." 

San could only stay conscious long enough to feel the razor sharp spine slide into the muscle of his throat.


	2. Optional Ending

**Notes for the Chapter:**

> For those of us with weak hearts

When San woke up, there was only darkness, an infinite, squirming black that shifted underneath and above and around him, as far as he could see. The darkness pressed heavily against his skin, in his mouth and chest and even against his open eyes. Panic seized him immediately and he curled up in a ball, trying to remember what had happened - what had - had he died? Was any of it real? He felt physically fine, if sluggish, but Yeosang had - had -

He weakly raised a hand, unable to see it in the darkness, and touched his throat. Instead of smooth skin, he felt jagged, open wounds, stiff - probably crusted with blood and worse - but no pain. Was he really dead? Was this what death was, just infinite blackness? He could feel his pulse ringing through his ears, but was it a hallucination? When he opened his mouth to scream, hardly any sound escaped and he thrashed wildly, throwing himself into the writhing darkness in desperation.

"Calm down, lovely," the darkness said, strands of it peeling away to snake around his wrists and over his chest. 

San stilled, the sensation triggering a wave of comfort through his mind. Seonghwa. It was real. All at once, he could feel the ocean around him, could sense the thousands of little lives scurrying over the sea bed and some larger, heavier energies much further out to sea. The sound of waves against stone washed over him like a lullaby, and San took a moment to realise that he felt  _ good _ , energized and alert. 

Piece by piece, the darkness released him - he had been inside a cocoon of sorts, Seonghwa's tentacles protecting him as he slept. Slowly, his eyes adjusted to the blue-green light and he could see they were both floating underwater, Seonghwa holding him gently in place with his tentacles. But if they were underwater then he - he didn't need to breathe? Seonghwa watched as he carefully raised his hands to his throat again, feeling the flow of water through the wounds in his throat. He imagined the rough-edged scars on Yeosang's neck and realization shot through him like a lightning bolt.

He smiled at Seonghwa, lifting his arm up to inspect the smooth, greenish skin, the darker, mottled patches that would camouflage him in the shallows. Seonghwa smiled back, his happy trill echoing clearly through the water. San examined the rest of his body - it was just like Yeosang's, sleek and sharp and powerful. He brought his hands up to his nose, feeling the strange ridges, and tested the edge of one needle-point tooth against his thumb. It drew blood, tiny beads of blueish black that floated and dissolved into the ocean.

"One of us, now," Seonghwa said, his pretty face radiant with pride. "Come to the surface, pretty thing, you'll have to learn to talk down here." 

He released San from his tentacles and San cast his eyes up at the surface, some ten meters above them. Then he kicked, delighted by the new power and grace coiled in his limbs as he snaked up faster than any human ever could. He could hear something, though, another large creature on the shore and he hesitated at the surface, peeking back to see what Seonghwa was doing. Seonghwa smiled at him again so he turned, poking his head up so that only his eyes came above the surface of the water. Yeosang was sitting in the shallows, whittling away at a piece of driftwood with a sharp shell, but when he heard San surface he cast both items into the water and ran excitedly into the deep pool, dropping his human face as he went. 

"San! I missed you!" he chirped, immediately crashing their bodies together. San gasped - and realised he was breathing again. 

"What? How can I do that?" he demanded, hands flying to his throat again. His speech was clumsy, lisp matching Yeosang's as his tongue struggled with too-large teeth.

"The sea told you," Yeosang said, "Whilst you were dreaming." 

"How long did I sleep?" he asked, running his hands curiously over the bone-like spines in his hair. 

"Three days," Yeosang said. "Your friends came looking for you but I sang to them. They think you decided to stay here and date me for a while." 

"You sang?" San asked, titling his head. "What do you mean?" 

"Like I did to you on the beach," Yeosang reminded him. San thought of the ocean crashing through his head as he told Yeosang all his secrets. 

"Of course." 

Seonghwa drifted over, tentacles caressing lazily over his two sirens.

"Aren't you hungry yet? You still need to bring me a black-hearted man, so I may renew the tide," he drawled, pouting like a child. 

San stared at him, confused, and Yeosang laughed. 

"Seonghwa only eats once every twelve moons," he said. "He consumes a black-hearted man to regain his power every winter."

"It used to be easy," Seonghwa complained, butting his face against San's hand like a cat. "They used to throw them from the cliffs for me. And when that stopped, there were plenty of ships to be sunk without anyone noticing." 

"Now it's my -  _ our _ job," Yeosang told San. "We find a black-hearted man and bring him back here to feast. Then the rest of the year, we can do whatever we want! Seonghwa's teaching me more shapeshifting. And we’re allowed to eat as many whalers as we want, so long as they don’t see us." 

" _ After  _ I eat," Seonghwa grumbled, insinuating himself between the two of them, tentacles coiling and squeezing fondly.

San hummed, tapping a finger against one jagged tooth.

"A black-hearted man, huh?" 

He thought about what that girl had said about local boys being untouchable and smiled. 

"I think I know where to start."

**Notes for the Chapter:**

> Who knew that ancient tentacle monsters are just giant finnicky sea cats, huh


End file.
